This invention relates to semiconductor die packaging and more specifically relates to a novel five-layer tape which enables the mounting and interconnection of plural semiconductor die relative to one another and to a lead frame support.
Metallization-on-tape is a type of an interconnect that is routinely used in the semiconductor industry in various applications such as tape-automated bonding (TAB). The use of polymer film for this purpose, such as polyimide as an insulative layer, is also known and is used in many semiconductor packaging solutions. Placing an adhesive layer on the film is also used to bond interconnects or insulation layers to the substrate and/or semiconductor die.
However, all three elementsxe2x80x94adhesive layers, insulative layers (such as polyimide film) and metallic fingers/interconnect have not been previously combined in a single tape.
In accordance with the invention, a novel five-layer sandwich of adhesive, insulation, metal, insulation and adhesive layers provides a whole new variety of potential applications such as bonding, interconnection and mutual insulation of different parts of the semiconductor package at the same time. In order to have a contact with a terminal on the semiconductor die or other bonding pad site, windows are formed in the insulative layer. Then thermocompression, for example, can be used to as a means to connect the metallic layer of the tape to the bonding site by conventional means. The novel tape can be produced, using a double-side adhesive insulative tape (for example, a polyimide film coated with adhesive) with windows formed in the film at designated sites where connection is to take place. A metallic layer is deposited/pressed down/glued onto the insulation layer as desired. Finally a single-sided or double-sided adhesive-coated insulated layer (also with precut windows if desired) is pressed on top of the metallic layer and the first insulative layer to produce the finished tape. The tape may be unreeled from a supply reel of any desired length, and then cut off in pieces of size suitable for a given application.